The Linux kernel nf_conntrack module can emit logs for malformed TCP or SCTP packets while it still holds the conntrack lock. When nfnetlink_log and conntrack export are enabled, the logging routine can re‑enter the conntrack core and attempt to dump the same entry again. Because both paths try to acquire the same lock, this recursive re‑entry can deadlock the kernel network stack, halting packet transmission and leading to a denial of service.

All Linux kernel releases that include nf_conntrack and nfnetlink_log may be affected. No specific version list is provided, so any kernel with the nf_conntrack module is potentially vulnerable until the vendor releases a patch.

The flaw can be triggered by sending crafted TCP or SCTP packets that cause an invalid state. While no EPSS score or KEV listing is present, the lack of public exploitation does not reduce the theoretical risk. The attack requires network access and the ability to generate malformed traffic, which can be achieved by a remote or local adversary. Because the vulnerability can freeze the kernel’s networking layer, the impact is severe but the exploit vector is limited to entities that can send those packets. The absence of a CVSS score makes precise quantification difficult, but the potential for service disruption warrants immediate attention.